1. Field
One or more embodiments of the invention relate to the field of time keeping devices. In particular, one or more embodiments of the invention relate to the field of atomic clocks.
2. Background Information
Atomic clocks have been around for many years. Early atomic clocks were manufactured in the 1940's.
Atomic clocks may keep time based on the hyperfine interaction between the outer electron(s) and the nuclear spin of an atom. The use of the hyperfine interaction generally allows extremely accurate time keeping. By way of example, some atomic clocks are able to keep time with a precision of 1 part in 1015, or better.
The ability to keep time so accurately has resulted in atomic clocks having numerous industrial applications. Representative applications include, but are not limited to, time keeping for wireless communication, networking, and global positioning systems (GPS), to name just a few examples.
However, many of the atomic clocks that are presently in widespread use tend to be relatively large and to have relatively complicated designs that are not very conducive to miniaturization. Much of the innovation in atomic clock design has focused primarily on increasing the time keeping accuracy of the atomic clocks, often at the expense of increased design complexity and/or insignificant reductions in the size of the atomic clocks. The large size and/or complex designs of the atomic clocks may tend to limit the use of atomic clocks in certain situations, such as, for example, in small portable electronic devices that need to be manufactured relatively inexpensively and that may have limited battery power available.